44 BRITISH CARBONIFEROUS BRACHIOPODA. 



sides suddenly attenuate, cuspidate ; mesial lobe large, round, projecting, with five large 

 rounded ribs on each side, leaving a broad space at the cardinal angles smooth, or only 

 striated transversely. This species is so very distinct from any other Spirifera with which 

 I am acquainted, that it would be unnecessary to point out any peculiar difference. The 

 whole surface is smooth except the cuspidate sides, which are marked with strong lines of 

 growth." 



Log. Lower limestone, Millecent (Clare), Ireland. 



Spirifera cuspid ata, Martin, sp. 1 Plate VIII, figs. 19 — 24; Plate IX, figs. 1 and 2. 



Anomites cuspidatus, Martin. Trans. Linnean Soc, vol. iv, p. 44, pi. iii, figs. 



1—4, 5, 6, 1796. 

 Conchtliolithus anomites cuspidatus, Martin. Petref. Derb., tab. xlvi, fig. 34, and 



tab. xlvii, fig. 5, 1809. 

 Spibifer cuspidatus, Sowerby. Min. Con., tab. 120, figs. 1, 2, 3, Feb., 1816. 

 Cyrtia simplex, M'Coy. Synopsis Carb. Foss. of Ireland, 1844 (not of Phillips). 

 — cuspidata, M'Coy. British Palaeozoic Fossils, p. 466, 1855. 



Spec. Char. Transverse and pyramidal ; hinge-line straight, in general rather shorter 

 than the greatest width of the shell. The cardinal angles, formed by the junction of the 

 lateral portions of the valves with the extremities of the hinge-line, are rounded off. 

 Dorsal valve semicircular, moderately convex ; mesial fold large, smooth, regularly convex, 

 and elevated, with a slight longitudinal depression or groove (especially visible in casts) 

 extending from the extremity of the umbone to about half the length of the fold. Each 

 valve is ornamented by numerous small, simple ribs, varying from thirty to forty-four in 

 number, according to age and individual, these being at the same time intersected by 

 numerous concentric lines of growth. The ventral valve is pyramidal, much deeper 

 than the opposite one, and possesses a large, wide, concave sinus, which extends from the 

 extremity of the frontal margin, producing in front a strongly marked wave. Area very 

 large, triangular, and acute, situated at a right angle to the general level of the dorsal 

 valve ; fissure large, but comparatively narrow in proportion to its length. 



In the interior of the ventral valve a strong tooth exists on either side, at each 

 extremity of the fissure. These are supported by dental plates, which diverge from the 

 extremity of the beak, forming the fissure walls, and occupying about one third of the 

 length of the bottom of the valve. The larger portion of the interior of the shell is 



1 This well-known Carboniferous fossil has been very often referred to and figured by various authors. 

 By Parkinson (1811), Bronn (1824), Kruger (1825), Defrance (1827), Fleming (1828), Holl (1830), 

 Keferst (1834), Deshayes apud Lamarck (1836), Phillips (1836), V. Buch (1837), Conrad (1838), &c, 

 a full reference to which will be found in page 243 of Professor De Koninck's works on the Belgian 

 Carboniferous Fossils. 



